USGS Science⌕ Search

SEARCH · USGS Science

Results for “Landscape Ecology”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources
USGS2011

Landscape matrix mediates occupancy dynamics of Neotropical avian insectivores

In addition to patch‐level attributes (i.e., area and isolation), the nature of land cover between habitat patches (the matrix) may drive colonization and extinction dynamics in fragmented landscapes. Despite a long‐standing recognition of matrix effects in fragmented systems, an understanding of the relative impacts of different types of land cover on patterns and dynamics of species occurrence remains limited. We employed multi‐season occupancy models to determine the relative influence of patch area, patch isolation, within‐patch vegetation structure, and landscape matrix on occupancy dynamics of nine Neotropical insectivorous birds in 99 forest patches embedded in four matrix types (agriculture, suburban development, bauxite mining, and forest) in central Jamaica. We found that within‐patch vegetation structure and the matrix type between patches were more important than patch area and patch isolation in determining local colonization and local extinction probabilities, and that the effects of patch area, isolation, and vegetation structure on occupancy dynamics tended to be matrix and species dependent. Across the avian community, the landscape matrix influenced local extinction more than local colonization, indicating that extinction processes, rather than movement, likely drive interspecific differences in occupancy dynamics. These findings lend crucial empirical support to the hypothesis that species occupancy dynamics in fragmented systems may depend greatly upon the landscape context.

Clarendon Parish, Manchester Parish↗
USGS2015

Fish assemblage shifts in the Powder River of Wyoming: an unregulated prairie river system previously considered to be relatively pristine.

W y oming ’ s P owder River is considered an example of a pristine prairie river system. While the river hosts a largely native fish assemblage and remains unimpounded over its 1,146-km course to the Y ellowstone River confluence, the hydrologic regime has been altered through w ater dive rsion for agriculture and natural gas extraction and there has been limited study of fish assemblage structure. W e analyzed fish data collected from the mainstem P owder River in W yoming between 1896 and 2008. Shifts in presence/absence and relative abundance of fish species, as well as fish assemblage composition, were assessed among historical and recent samples. The recent P owder Rive r fish assemblage w as characterized by increased relative abundances of sand shiner Notr opis stramineus and plains killifish Fundulus zebrinus , and decreases in sturgeon chub Macrhybopsis gelida . Shifts in fish species relative abundance are linked to their reproductive ecology with species with adhesive eggs generally increasing in relative abundance while those with buoy ant drifting eggs are decreasing. Assemblage shifts could be the result of landscape level changes, such as the loss of extreme high and low flow events and changing land use practices.

Montana, Wyoming↗
USGS2018

Batrachochytrium salamandriovrans (Bsal) in Appalachia—Using scenario building to proactively prepare for a wildlife disease outbreak caused by an invasive amphibian chytrid fungus

Batrachochytrium salamandrivorans ( Bsal ), a pathogenic chytrid fungus, is nonnative to the United States and poses a disease threat to vulnerable amphibian hosts. The Bsal fungus may lead to increases in threatened, endangered, and sensitive status listings at State, Tribal, and Federal levels, resulting in financial costs associated with implementing the Endangered Species Act of 1973. The United States is a global biodiversity hotspot for salamanders, an order of amphibians that is particularly vulnerable to developing a disease called chytridiomycosis when exposed to Bsal . Published Bsal risk assessments for North America have suggested that salamanders within the Appalachian region of the United States are at a high risk. In May 2017, a workshop was facilitated by the Department of the Interior’s Strategic Sciences Group. During the workshop, a discussion-based incident-response exercise focused on a hypothetical Bsal disease outbreak in Appalachia was led by U.S. Geological Survey staff members. Participants included representatives of the Eastern Band of the Cherokee Indians, U.S. Fish and Wildlife Service, National Park Service, Appalachian Landscape Conservation Cooperative, Tennessee Wildlife Resources Agency, and U.S. Department of Agriculture’s U.S. Forest Service. Scenario building was used to brainstorm cascading consequences (social, economic, and ecological) of a Bsal disease outbreak in the Appalachian region. This report highlights the management and science actions that could be undertaken to ensure an effective, rapid response to a Bsal introduction into the United States.

Open-File Report↗
USGS2010

Southwestern desert resources

The southwestern deserts stretch from southeastern California to west Texas and then south to central Mexico. The landscape of this region is known as basin and range topography featuring to "sky islands" of forest rising from the desert lowlands which creates a uniquely diverse ecology. The region is further complicated by an international border, where governments have caused difficulties for many animal populations. This book puts a spotlight on individual research projects which are specific examples of work being done in the area and when they are all brought together, to shed a general light of understanding the biological and cultural resources of this vast region so that those same resources can be managed as effectively and efficiently as possible. The intent is to show that collaborative efforts among federal, state agency, university, and private sector researchers working with land managers, provides better science and better management than when scientists and land managers work independently.

Book↗
USGS2010

Sediment transport on Cape Sable, Everglades National Park, Florida

The Cape Sable peninsula is located on the southwestern tip of the Florida peninsula within Everglades National Park (ENP). Lake Ingraham, the largest lake within Cape Sable, is now connected to the Gulf of Mexico and western Florida Bay by canals built in the early 1920's. Some of these canals breached a natural marl ridge located to the north of Lake Ingraham. These connections altered the landscape of this area allowing for the transport of sediments to and from Lake Ingraham. Saline intrusion into the formerly fresh interior marsh has impacted the local ecology. Earthen dams installed in the 1950's and 1960's in canals that breached the marl ridge have repeatedly failed. Sheet pile dams installed in the early 1990's subsequently failed resulting in the continued alteration of Lake Ingraham and the interior marsh. The Cape Sable Canals Dam Restoration Project, funded by ENP, proposes to restore the two failed dams in Lake Ingraham. The objective of this study was to collect discharge and water quality data over a series of tidal cycles and flow conditions to establish discharge and sediment surrogate relations prior to initiating the Cape Sable Canals Dam Restoration Project. A dry season synoptic sampling event was performed on April 27-30, 2009.

Florida↗
USGS2002

Application of landscape models to alternative futures analyses

Scientists and environmental managers alike are concerned about broadscale changes in land use and landscape pattern and their cumulative impact on environmental and economic end points, such as water quality and quantity, species habitat, productivity, erosion potential, recreational value, and overall ecological health (Rapport et al., 1998). They also are interested in predicting short-and long-term future impacts on ecological goods and services based on current land management policies and decisions (Steinitz, 1996). Because we have the means to adjust land management policies, it is worthwhile to develop approaches that can predict the consequences (alternative futures) of different land management policies for different environmental end points. This type of analysis can, for example, allow decision makers in resource conservation and restoration programs to estimate how they can get the most ecological benefit for the least cost

Delaware, Maryland, New York, Pennsylvania, Virgin↗
USGS2019

Impact of prey occupancy and other ecological and anthropogenic factors on Tiger distribution in Thailand’s Western Forest Complex

Despite conservation efforts, large mammals such as tigers (Panthera tigris) and their main prey, gaur (Bos gaurus), banteng (Bos javanicus), and sambar (Rusa unicolor), are highly threatened and declining across their entire range. The only large viable source population of tigers in mainland Southeast Asia occurs in Thailand's Western Forest Complex (WEFCOM), an approximately 19,000 km 2 landscape of 17 contiguous protected areas. We used an occupancy modeling framework, which accounts for imperfect detection, to identify the factors that affect tiger distribution at the approximate scale of a female tiger's home range, 64 km 2 , and site use at a scale of 1-km 2 . At the larger scale, we estimated the proportion of sites at WEFCOM that were occupied by tigers; at the finer scale, we identified the key variables that influence site-use and developed a predictive distribution map. At both scales, we examined key anthropogenic and ecological factors that help explain tiger distribution and habitat use, including probabilities of gaur, banteng, and sambar occurrence from a companion study. Occupancy estimated at the 64-km 2 scale was primarily influenced by the combined presence of all three large prey species, and 37% or 5,858 km 2 of the landscape was predicted to be occupied by tigers. In contrast, site use estimated at the scale of 1 km 2 was most strongly influenced by the presence of sambar. By modeling occupancy while accounting for imperfect probability of detection, we established reliable benchmark data on the distribution of tigers in WEFCOM. This study also identified factors that limit tiger distributions; which managers can then target to expand tiger distribution and guide recovery elsewhere in Southeast Asia.

Ecology and Evolution↗
USGS2004

Estimating functional connectivity of wildlife habitat and its relevance to ecological risk assessment

Habitat fragmentation is a major threat to the viability of wildlife populations and the maintenance of biodiversity. Fragmentation relates to the sub-division of habitat into disjunct patches. Usually coincident with fragmentation per se is loss of habitat, a reduction in the size of the remnant patches, and increasing distance between patches. Natural and anthropogenic processes leading to habitat fragmentation occur at many spatial scales, and their impacts on wildlife depend on the scales at which species interact with the landscape. The concept of functional connectivity captures this organism-based view of the relative ease of movement or degree of exchange between physically disjunct habitat patches. Functional connectivity of a given habitat arrangement for a given wildlife species depends on details of the organism's life history and behavioral ecology, but, for broad categories of species, quantities such as home range size and dispersal distance scale allometrically with body mass. These relationships can be incorporated into spatial analyses of functional connectivity, which can be quantified by indices or displayed graphically in maps. We review indices and GIS-based approaches to estimating functional connectivity, presenting examples from the literature and our own work on mammalian distributions. Such analyses can be readily incorporated within an ecological risk framework. Estimates of functional connectivity may be useful in a screening-level assessment of the impact of habitat fragmentation relative to other stressors, and may be crucial in detailed population modeling and viability analysis.

ASTM Selected Technical Papers↗
USGS2018

Spatiotemporal remote sensing of ecosystem change and causation across Alaska

Contemporary climate change in Alaska has resulted in amplified rates of press and pulse disturbances that drive ecosystem change with significant consequences for socio‐environmental systems. Despite the vulnerability of Arctic and boreal landscapes to change, little has been done to characterize landscape change and associated drivers across northern high‐latitude ecosystems. Here we characterize the historical sensitivity of Alaska's ecosystems to environmental change and anthropogenic disturbances using expert knowledge, remote sensing data, and spatiotemporal analyses and modeling. Time‐series analysis of moderate—and high‐resolution imagery was used to characterize land‐ and water‐surface dynamics across Alaska. Some 430,000 interpretations of ecological and geomorphological change were made using historical air photos and satellite imagery, and corroborate land‐surface greening, browning, and wetness/moisture trend parameters derived from peak‐growing season Landsat imagery acquired from 1984 to 2015. The time series of change metrics, together with climatic data and maps of landscape characteristics, were incorporated into a modeling framework for mapping and understanding of drivers of change throughout Alaska. According to our analysis, approximately 13% (~174,000 ± 8700 km 2 ) of Alaska has experienced directional change in the last 32 years (±95% confidence intervals). At the ecoregions level, substantial increases in remotely sensed vegetation productivity were most pronounced in western and northern foothills of Alaska, which is explained by vegetation growth associated with increasing air temperatures. Significant browning trends were largely the result of recent wildfires in interior Alaska, but browning trends are also driven by increases in evaporative demand and surface‐water gains that have predominately occurred over warming permafrost landscapes. Increased rates of photosynthetic activity are associated with stabilization and recovery processes following wildfire, timber harvesting, insect damage, thermokarst, glacial retreat, and lake infilling and drainage events. Our results fill a critical gap in the understanding of historical and potential future trajectories of change in northern high‐latitude regions.

Alaska↗
USGS2025

Quantifying landscape-level biodiversity change in an island ecosystem: A 50-year assessment of shifts in the Hawaiian avian community

Hawaii has experienced profound declines in native avifauna alongside the introduction of numerous bird species. While site-specific population studies are common, landscape-level analyses of avian population dynamics are rare, particularly in island ecosystems. To address this gap, we used a density surface model to create a spatio-temporal projection of population densities and distributions across the Island of Hawai‘i, spanning nearly five decades (1976–2023). We incorporated environmental covariates of habitat, precipitation, and elevation, to further refine our projections. Our analysis encompassed nine native and six non-native bird species, inhabiting a range of ecological niches. We found five out of nine native species have declined in density and range size while four were stable. For non-native species, two were stable, one was decreasing, and three were increasing in density and range size. Our landscape projections can inform management by suggesting areas critical for habitat preservation and land acquisition for conservation, identifying where range fragmentation is occurring, and pinpointing locations of multi-species declines that are likely driven by a common cause. Our study demonstrates how long-term, landscape-level monitoring and analyses can advance understanding and addressing biodiversity loss, particularly in vulnerable tropical island ecosystems.

Hawaii↗
USGS2024

Adaptation and Response in Drylands (ARID): Community insights for scoping a NASA terrestrial ecology field campaign in drylands

Dryland ecosystems cover 40% of our planet's land surface, support billions of people, and are responding rapidly to climate and land use change. These expansive systems also dominate core aspects of Earth's climate, storing and exchanging vast amounts of water, carbon, and energy with the atmosphere. Despite their indispensable ecosystem services and high vulnerability to change, drylands are one of the least understood ecosystem types, partly due to challenges studying their heterogeneous landscapes and misconceptions that drylands are unproductive “wastelands.” Consequently, inadequate understanding of dryland processes has resulted in poor model representation and forecasting capacity, hindering decision making for these at-risk ecosystems. NASA satellite resources are increasingly available at the higher resolutions needed to enhance understanding of drylands' heterogeneous spatiotemporal dynamics. NASA's Terrestrial Ecology Program solicited proposals for scoping a multi-year field campaign, of which Adaptation and Response in Drylands (ARID) was one of two scoping studies selected. A primary goal of the scoping study is to gather input from the scientific and data end-user communities on dryland research gaps and data user needs. Here, we provide an overview of the ARID team's community engagement and how it has guided development of our framework. This includes an ARID kickoff meeting with over 300 participants held in October 2023 at the University of Arizona to gather input from data end-users and scientists. We also summarize insights gained from hundreds of follow-up activities, including from a tribal-engagement focused workshop in New Mexico, conference town halls, intensive roundtables, and international engagements.

Earth's Future↗
USGS2019

Improving ecological restoration to curb biotic invasion - A practical guide

Common practices for invasive species control and management include physical, chemical, and biological approaches. The first two approaches have clear limitations and may lead to unintended (negative) consequences, unless carefully planned and implemented. For example, physical removal rarely completely eradicates the targeted invasive species and can cause disturbances that facilitate new invasions by nonnative species from nearby habitats. Chemical treatments can harm native, and especially rare, species through unanticipated side effects. Biological methods may be classified as biocontrol and the ecological approach. Similar to physical and chemical methods, biocontrol also has limitations and sometimes leads to unintended consequences. Therefore, a relatively safer and more practical choice may be the ecological approach, which has two major components: (1) restoration of native species and (2) biomass manipulation of the restored community, such as selective grazing or prescribed burning (to achieve and maintain viable population sizes). Restoration requires well-planned and implemented planting designs that consider alpha-, beta-, and gamma-diversity and the abundance of native and invasive component species at local, landscape, and regional levels. Given the extensive destruction or degradation of natural habitats around the world, restoration could be most effective for enhancing ecosystem resilience and resistance to biotic invasions. At the same time, ecosystems in human-dominated landscapes, especially those newly restored, require close monitoring and careful intervention (e.g., through biomass manipulation), especially when successional trajectories are not moving as intended. Biomass management frequently uses prescribed burning, grazing, harvesting, and thinning to maintain overall ecosystem health and sustainability. Thus, the resulting optimal, balanced, and relatively stable ecological conditions could more effectively limit the spread and establishment of invasive species. Here we review the literature (especially within the last decade) on ecological approaches that involve biodiversity, biomass, and productivity, three key community/ecosystem variables that reciprocally influence one another. We focus on the common and most feasible ecological practices that can aid in resisting new invasions and/or suppressing the dominance of existing invasive species. We contend that, because of the strong influences from neighboring areas (i.e., as exotic species pools), local restoration and management efforts in the future need to consider the regional context and projected climate changes.

Invasive Plant Science and Management↗
USGS2007

Land-Cover Change in the Southern Lake Tahoe Basin, California and Nevada, 1940-2002

The Lake Tahoe basin has been subject to significant landscape-altering human activity since the mid-1850s; in particular, widespread timber harvest from the 1850s to 1920s and urban development from the 1950s to the present. The consequences of changes such as impacted water quality, degraded biotic communities, and increased fire hazard resulting from modern activity have prompted rising levels of concern for the ecological integrity of the region. The goal of this project is to map, quantify, and describe the spatial and temporal distribution and variability of historical changes in land use and land cover in the southern Lake Tahoe basin for the period from 1940 to 2002 in an effort to establish an understanding of regional landscape change. This map shows areas of land-use/land-cover change in a 279-km2 portion of the Lake Tahoe basin identified using change-detection analysis of multitemporal land-use/land-cover datasets for four dates (1940, 1969, 1987, and 2002), which yielded three periods for analysis. Land use/land cover was mapped using manual (visual) interpretation techniques in a geographic information system (GIS) from multiple imagery sources: black-and-white digital orthophotos for 1940 and 1969, natural-color digital orthophotos for 1987, and IKONOS multispectral satellite imagery for 2002. The landscape was classified using a 0.4-hectare (1-acre) minimum mapping unit and a hierarchical classification system. Impervious-surface data was derived directly from the 2002 IKONOS imagery on a per-pixel basis using digital image processing and GIS data integration.

Scientific Investigations Map↗
USGS2002

Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data

Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems. One historical data set of this type is the Public Land Survey (PLS) of the United States General Land Office, which contains data on multiple tree species, sizes, and distances recorded at each survey point, located at half-mile (0.8 km) intervals on a 1-mi (1.6 km) grid. This survey method was begun in the 1790s on US federal lands extending westward from Ohio. Thus, the data have the potential of providing a view of much of the US landscape from the mid-1800s, and they have been used extensively for this purpose. However, historical data sources, such as those describing the species composition of forests, can often be limited in the detail recorded and the reliability of the data, since the information was often not originally recorded for ecological purposes. Forest trees are sometimes recorded ambiguously, using generic or obscure common names. For the PLS data of northern Wisconsin, USA, we developed a method to classify ambiguously identified tree species using logistic regression analysis, using data on trees that were clearly identified to species and a set of independent predictor variables to build the models. The models were first created on partial data sets for each species and then tested for fit against the remaining data. Validations were conducted using repeated, random subsets of the data. Model prediction accuracy ranged from 81% to 96% in differentiating congeneric species among oak, pine, ash, maple, birch, and elm. Major predictor variables were tree size, associated species, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities formerly present in maps of historic ecosystems for the region and can be applied to PLS datasets elsewhere, as well as other sources of ambiguous historical data. Mapping the newly classified data with ecological land units provides additional information on the distribution, abundance, and associations of tree species, as well as their relationships to environmental gradients before the industrial period, and clarifies the identities of species formerly mapped only to genus. We offer some caveats on the appropriate use of data derived in this way, as well as describing their potential.

Ecosystems↗
USGS2011

Proposed initiative would study Earth's weathering engine

At the Earth's surface, a complex suite of chemical, biological, and physical processes combines to create the engine that transforms bedrock into soil (Figure 1). Earth's weathering engine provides nutrients to nourish ecosystems and human society mediates the transport of toxic components within the biosphere, creates water flow paths that carve and weaken bedrock, and contributes to the evolution of landscapes at all temporal and spatial scales. At the longest time scales, the weathering engine sequesters CO 2 , thereby influencing long-term climate change. Despite the importance of soil, our knowledge of the rate of soil formation is limited because the weathering zone forms a complex, ever-changing interface, and because scientific approaches and funding paradigms have not promoted integrated research agendas to investigate such complex interactions. No national initiative has promoted a systems approach to investigation of weathering science across the broad array of geology, soil science, ecology and hydrology. Such a program is certainly needed, and this article describes a platform on which to build the initiative to answer the following question: How does the Earth weathering engine break down rock to nourish ecosystems, carve terrestrial landscapes, and control carbon dioxide in the global atmosphere?

Eos Science News↗
USGS2026

Understanding natal emigration in group-living carnivores

Dispersal is a critical ecological and evolutionary process, yet the drivers of individual variation in emigration, particularly under human-modified conditions, remain relatively understudied. We investigate the determinants and patterns of emigration in a managed population of cooperative breeders using genetic samples from harvested individuals. We used a novel genetic approach to identify natal emigration through sibship analyses of DNA from harvested grey wolves ( Canis lupus ), a cooperative-breeding species, and evaluated how prey biomass, wolf density, human-caused mortality and sex influenced natal emigration across Idaho, USA, from 2017 to 2023. From our analysis of 182 sibling groups (representing packs), we evaluated natal emigration status for 224 individuals. Of these, 86 were classified as emigrants and 138 as non-dispersers. We assessed how covariates influenced the probability of emigration and evaluated sex differences in apparent dispersal distance. We found no sex differences in emigration propensity or apparent dispersal distance. Emigrants dispersed an average of 81.8 km (range: 30.0–338.9 km) from their inferred natal territories. Emigration was more likely from territories with higher prey biomass and lower wolf density, while human-caused mortality had no detectable effect. We found that ecological drivers, such as prey availability and population density, have a stronger effect on the propensity to emigrate than harvest intensity. These results highlight the importance of resource availability and population dynamics in shaping dispersal patterns in a cooperative breeder. Our study used a novel genetic method to assess natal emigration in a group-living carnivore and developed a framework broadly applicable to social systems where kin structures can be traced to dispersers. Our findings identify landscape-scale conditions that influence dispersal and can inform the management of wild populations.

Idaho↗
USGS2009

Fires and landscape conservation in mediterranean ecosystems

Protected areas are some of the last remaining areas on Earth where fire can play its natural role at a landscape-scale. The International Union for Conservation of Nature (IUCN) has developed a system for categorizing protected areas. The role fire can play in the various categories depends on the management objectives of the category, the size of the individual units, and the laws and policies of the country in which the unit is located. An analysis of all the IUCN protected areas showed that 505 areas had the potential for conserving landscape fire. Areas in Europe, Africa, South America, Australia, and North America show promise for being able to include fire in the conservation of landscapes. Examples from South Africa, Australia, and the United States show how fire can be incorporated at the landscape scale. Future challenges include increasing urban encroachment, climate change, and air pollution. Society will have to deal with these challenges if fire is to continue its essential ecological role in Mediterranean ecosystems.

Book chapter↗
USGS2013

Resilience to stress and disturbance, and resistance to Bromus tectorum L. invasion in cold desert shrublands of western North America

Alien grass invasions in arid and semi-arid ecosystems are resulting in grass–fire cycles and ecosystem-level transformations that severely diminish ecosystem services. Our capacity to address the rapid and complex changes occurring in these ecosystems can be enhanced by developing an understanding of the environmental factors and ecosystem attributes that determine resilience of native ecosystems to stress and disturbance, and resistance to invasion. Cold desert shrublands occur over strong environmental gradients and exhibit significant differences in resilience and resistance. They provide an excellent opportunity to increase our understanding of these concepts. Herein, we examine a series of linked questions about (a) ecosystem attributes that determine resilience and resistance along environmental gradients, (b) effects of disturbances like livestock grazing and altered fire regimes and of stressors like rapid climate change, rising CO 2 , and N deposition on resilience and resistance, and (c) interacting effects of resilience and resistance on ecosystems with different environmental conditions. We conclude by providing strategies for the use of resilience and resistance concepts in a management context. At ecological site scales, state and transition models are used to illustrate how differences in resilience and resistance influence potential alternative vegetation states, transitions among states, and thresholds. At landscape scales management strategies based on resilience and resistance—protection, prevention, restoration, and monitoring and adaptive management—are used to determine priority management areas and appropriate actions.

Ecosystems↗